Device and method for measuring leakage current of three-phase medical equipment

Abstract

According to the three-phase medical equipment leakage current measuring device and method, a relay, an ampere meter and a voltmeter are arranged between a network power source and tested equipment, the relay is controlled by a central control unit, a standard circuit can measure current and voltage of the tested equipment, and data of the current and the voltage are fed back to the central control unit. The device is divided into three layers, the first layer is provided with a display module, the second layer comprises a central control unit and other core components, and the third layer is provided with a relay and the like. The on-off of the relay can be controlled through the central control unit, the power-on state of the tested equipment can be automatically switched, data can be measured, the binding post can be connected with a line at a time, the operation is simple, convenient and safe, and a weighted circuit and a non-weighted circuit can be switched. Besides, a measuring part is arranged between the relay and the wiring part, and the actual current and voltage of the network power supply are used as the reference to compare the leakage current measurement result, thereby avoiding misjudgment caused by default network power supply voltage, and improving the measurement accuracy and reliability.

Description

Technical Field

[0001] The present invention relates to the technical field of leakage current detection of three-phase medical equipment, and in particular to a leakage current measuring device and method of three-phase medical equipment. Background Art

[0002] The leakage current test of medical equipment is carried out in accordance with the provisions of "GB 9706.1-2020 Medical Electrical Equipment Part 1: General Safety Requirements", with the aim of ensuring that the leakage current of medical equipment will not cause electric shock hazards to patients and operators under normal use and single fault conditions. The test content is the ground leakage current, contact leakage current and patient leakage current under normal and single fault conditions.

[0003] The electrical parts of single-phase equipment are sealed in the insulating shell of the finished product, similar to an adapter. The electrical parts of three-phase medical equipment are in an exposed environment, and for inspectors, the test process is in a more dangerous environment with risk of electric shock.

[0004] In addition, three-phase medical equipment needs to measure two types of leakage currents. Each leakage current is divided into normal mode and single fault mode. The single fault mode has four states. The current method of measuring each state is: 1. Turn off the main power supply; 2. Then according to the test method specified in the standard, use a screwdriver to manually disconnect a phase line in the distribution cabinet; 3. Insulate the disconnected phase line; 4. Turn on the main power supply and record the test value. After measuring the two types of leakage currents, a total of 8 states, this operation must be repeated 8 times, increasing the risk of electric shock. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for measuring leakage current of three-phase medical equipment, so as to simplify the detection of leakage current of three-phase medical equipment and reduce the risk of detection personnel being electrostatically damaged.

[0006] A three-phase medical equipment leakage current measuring device, wherein a relay, an ammeter, and a voltmeter are arranged between the live wire L1, live wire L2, live wire L3, neutral wire N, and ground wire PE of a power grid and the live wire L1, live wire L2, live wire L3, neutral wire N, and ground wire PE of a corresponding device under test, wherein switches K1, K2, K3, K4, and K5 of the relay are respectively connected in series between the live wire L1, live wire L2, live wire L3, neutral wire N, and ground wire PE of the power grid and the live wire L1, live wire L2, live wire L3, neutral wire N, and ground wire PE of the corresponding device under test, Ammeters A1, A2, A3, A4 are connected in series with the live wire L1, live wire L2, live wire L3, neutral wire N of the grid power supply and the live wire L1, live wire L2, live wire L3, neutral wire N of the corresponding equipment under test, respectively; voltmeters V1, V2, V3, V4 are connected in parallel with the corresponding ammeters; coils KM1, KM2, KM3, KM4, KM5 of the relays are controlled by the control ports Y1, Y2, Y3, Y4, Y5 of the central control unit, respectively; voltmeters V1, V2, V3, V4 and the corresponding ammeters feed data back to the central control unit;

[0007] The measuring device also includes a standard circuit, whose input terminal A and output terminal B are respectively connected to the test points M1 and M2 of the device under test. The standard circuit has a voltmeter V and an ammeter A. The data measured by the voltmeter V and the ammeter A in the standard circuit are fed back to the central control unit.

[0008] Furthermore, the standard circuit includes a resistor R1, a resistor R2, a capacitor C1, a switch 1, and a switch 2. The switch 2 and the resistor R1 and the capacitor C1 are connected in series to form a path N. The path N is connected in series with the ammeter A. The resistor R2 is connected in parallel with the path N. The voltmeter V is connected in parallel with the capacitor C1. The switch 2 and the resistor R1 are connected in series to form a path N1. The switch 1 is connected in parallel with the path N1. One end of the switch 2 is the input end A, and one end of the ammeter A is the output end B.

[0009] Furthermore, the switch 1 and the switch 2 are controlled triodes.

[0010] Furthermore, the controlled end of the controlled triode is connected to the central control unit to be controlled by the central control unit.

[0011] Furthermore, the measuring device is divided into a first layer, a second layer and a third layer from top to bottom, the first layer and the second layer are fixedly installed, and the second layer and the third layer are hingedly installed.

[0012] Furthermore, the third layer includes relays, terminals or terminal clamps, ammeters A1, A2, A3, A4 and voltmeters V1, V2, V3, V4. The terminals or terminal clamps are provided in two groups and are respectively arranged at the front end and the rear end of the test equipment. Each group of terminals or terminal clamps has five live wires L1, L2, L3, neutral wire N, and ground wire PE corresponding to the mains power supply and the equipment under test. The terminals or terminal clamps are connected to the corresponding wiring. The switches K1, K2, K3, K4 of the relays and the ammeters A1, A2, A3, A4 are arranged in series between every two corresponding terminals. The switch K5 of the relay is arranged between the remaining corresponding terminals. The voltmeters V1, V2, V3, V4 are connected in parallel with the ammeters A1, A2, A3, A4 one by one.

[0013] Furthermore, the second layer includes a central control unit and a standard circuit, and an input terminal A and an output terminal B of the standard circuit are also provided on the side of the second layer.

[0014] Furthermore, the first layer includes a display module, which receives and displays data transmitted by the central control unit.

[0015] A measurement method for a three-phase medical equipment leakage current measurement device, performing the following steps:

[0016] SK. The leakage current measurement is divided into weighted mode and non-weighted mode. The central control unit controls the controlled transistor Q2 in the standard circuit to be turned on and the controlled transistor Q1 to be turned off for the weighted mode, and the controlled transistor Q2 to be turned off and the controlled transistor Q1 to be turned on for the non-weighted mode. When the weighted mode or / and non-weighted mode are selected, S1 to S5 are executed:

[0017] S1. The central control unit sends a signal to control the relay coils KM1, KM2, KM3, KM4, so that the relay switches K1, K2, K3, K4 are closed, the relay switch K5 is kept normally off, and the ammeters A1, A2, A3, A4 and the voltmeters V1, V2, V3, V4 as well as the voltmeter V and the ammeter A are measured;

[0018] S2. After completing the measurement of the last power-on state, control the relay coils KM1, KM2, KM3, and KM4 in sequence, disconnect the relay switches K1, K2, K3, and K4 one by one, disconnect only one relay switch at a time, and keep the other switches closed, and measure the ammeters A1, A2, A3, and A4 and the voltmeters V1, V2, V3, and V4 as well as the voltmeter V and the ammeter A in sequence;

[0019] S3. The central control unit controls the relay coils KM1, KM2, KM3, KM4, KM5 to turn on the relay switches K1, K2, K3, K4, K5, keep the relay K5 normally on, and measure the ammeters A1, A2, A3, A4 and the voltmeters V1, V2, V3, V4 as well as the voltmeter V and the ammeter A;

[0020] S4. After each measurement is completed, the relay coils KM1, KM2, KM3, and KM4 are controlled in sequence to disconnect the relay switches K1, K2, K3, and K4 one by one, and only one relay switch is disconnected at a time, while keeping the other switches closed, and the ammeters A1, A2, A3, and A4 and the voltmeters V1, V2, V3, and V4 as well as the voltmeter V and the ammeter A are measured in sequence;

[0021] S5. After completing all the measurements, the central control unit controls the coils KM1, KM2, KM3, KM4, and KM5 of the relay to disconnect the switches K1, K2, K3, K4, and K5 of the relay.

[0022] The present invention has the beneficial effects:

[0023] 1. The present invention can simplify the existing steps of measuring leakage current of three-phase medical equipment. The measuring device control circuit replaces the manual phase cutting process, thereby reducing the direct contact between the detection personnel and the electrical parts, reducing the risk of the detection personnel being electric shocked, and ensuring the safety of the detection personnel.

[0024] 2. The layered design makes the measuring device modular in function, reduces the complexity of the measuring device, and improves the maintainability of the measuring device. The side-opening design of the third layer enables rapid replacement of the terminal or terminal clamp when there is a problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a circuit diagram of the present invention;

[0026] Figure 2 This is a schematic diagram of a standard circuit of the present invention;

[0027] Figure 3 It is an overall schematic diagram of the measuring device of the present invention;

[0028] Figure 4 A top view of the measuring device of the present invention;

[0029] Figure 5 A top perspective view of the third layer of the measuring device of the present invention;

[0030] Figure numerals: 1-first layer, 2-second layer, 3-third layer, 4-hinge, 5-binding post or wiring clamp, 6-network power supply, 7-device under test, 8-external cable, 9-print outlet, 10-display screen, 11-indicator light, 12-button. DETAILED DESCRIPTION

[0031] The present invention will be further described in detail below in conjunction with embodiments and drawings, but the implementation manner of the present invention is not limited to these embodiments.

[0032] Example 1

[0033] See also Figures 1 to 4 As shown,

[0034] A three-phase medical equipment leakage current measuring device, wherein a relay, an ammeter, and a voltmeter are arranged between the live wire L1, live wire L2, live wire L3, and neutral wire N of a network power supply and the live wire L1, live wire L2, live wire L3, and neutral wire N of a corresponding device under test, and a relay is arranged between the ground wire PE of the network power supply and the ground wire PE of the corresponding device under test, wherein switches K1, K2, K3, K4, and K5 of the relay are respectively connected in series with the live wire L1, live wire L2, live wire L3, and neutral wire N of the network power supply and the ground wire PE of the corresponding device under test and the live wire L1, live wire L2, live wire L3, and neutral wire N of the network power supply. The current meters A1, A2, A3, A4 are respectively connected in series between the live wire L1, live wire L2, live wire L3, neutral wire N of the network power supply and the live wire L1, live wire L2, live wire L3, neutral wire N of the corresponding equipment under test, the voltage meters V1, V2, V3, V4 are connected in parallel with the corresponding current meters, the coils KM1, KM2, KM3, KM4, KM5 of the relays are respectively controlled by the control ports Y1, Y2, Y3, Y4, Y5 of the central control unit, and the voltage meters V1, V2, V3, V4 and the corresponding current meters feed back data to the central control unit;

[0035] The measuring device also includes a standard circuit, whose input terminal A and output terminal B are respectively connected to the test points M1 and M2 of the device under test. The standard circuit has a voltmeter V and an ammeter A. The data measured by the voltmeter V and the ammeter A in the standard circuit are fed back to the central control unit.

[0036] Different measurement modes are selected according to the selected mode, and then the central control unit is used to control the on and off of the relays in the relay module group to realize different power-on states of the device under test, thereby replacing the manual phase cutting in the existing measurement method. The device under test is connected to the measurement module to measure the data of the device under test in different power-on states and feed it back to the central control unit for calculation, and finally displayed on the display screen or printed out.

[0037] The test device can connect all the lines between the network power supply and the device under test at one time through the terminal posts. Unlike the existing test method, it is not necessary to manually connect and cut the wires after testing each power-on state of the device under test, which simplifies the operation of the tester. The central control unit can independently control the five relays to realize the on and off of each line, thereby simulating the on and off conditions of the device under test in different lines, and realizing automatic switching of the power-on states of different devices under test, replacing the manual switching in the existing test method, ensuring the safety of the tester and ensuring that each power-on state of the device under test can be measured without omission.

[0038] The present invention also sets a component for measuring voltage and current between the relay and the terminal or the terminal clamp, which can detect the current and voltage of the mains power supply, and use this as a reference to compare with the result measured by the leakage current circuit. Compared with the existing measurement method of the default mains power supply being 220V, it avoids misjudgment of the result due to the instability of the mains power supply.

[0039] Furthermore, the standard circuit includes a resistor R1, a resistor R2, a capacitor C1, a switch 1, and a switch 2. The switch 2 and the resistor R1 and the capacitor C1 are connected in series to form a path N. The path N is connected in series with the ammeter A. The resistor R2 is connected in parallel with the path N. The voltmeter V is connected in parallel with the capacitor C1. The switch 2 and the resistor R1 are connected in series to form a path N1. The switch 1 is connected in parallel with the path N1. One end of the switch 2 is the input end A, and one end of the ammeter A is the output end B.

[0040] GB 9706.1-2020 Medical Electrical Equipment Part 1: General Safety Requirements specifies weighted and non-weighted circuits for leakage current measurement. The present invention combines the two circuits into one. Figure 2 As shown, the weighted and non-weighted circuits are switched by a central control unit.

[0041] Furthermore, switch 1 and switch 2 are controlled diodes or controlled triodes.

[0042] Furthermore, the controlled end of the controlled triode is connected to the central control unit to receive control of the central control unit.

[0043] Furthermore, the measuring device is divided into a first layer, a second layer and a third layer from top to bottom, the first layer and the second layer are fixedly installed, and the second layer and the third layer are hingedly installed.

[0044] The device is designed with three layers, mainly based on functional division, ease of operation, maintainability and safety. The first and second layers are fixedly installed to avoid functional failure due to operational errors or external interference; the second and third layers are movably installed, and the third layer can be opened from the side to facilitate the replacement of terminal posts or clamps on the third layer.

[0045] Furthermore, the third layer includes relays, terminals or terminal clamps, ammeters A1, A2, A3, A4 and voltmeters V1, V2, V3, V4. The terminals or terminal clamps are provided in two groups and are respectively arranged at the front end and the rear end of the test equipment. Each group of terminals or terminal clamps has five live wires L1, L2, L3, neutral wire N, and ground wire PE corresponding to the mains power supply and the equipment under test. The terminals or terminal clamps are connected to the corresponding wiring. The switches K1, K2, K3, K4 of the relays and the ammeters A1, A2, A3, A4 are arranged in series between every two corresponding terminals. The switch K5 of the relay is arranged between the remaining corresponding terminals. The voltmeters V1, V2, V3, V4 are connected in parallel with the ammeters A1, A2, A3, A4 one by one.

[0046] For electrical safety protection, the terminal posts or terminal clamps are embedded in the device, and wiring holes are opened to facilitate the operation of the inspectors.

[0047] Furthermore, the second layer includes a central control unit and a standard circuit, and an input terminal A and an output terminal B of the standard circuit are also arranged on the side of the second layer.

[0048] The central control unit is the core, responsible for processing information and controlling other components; the input terminal A and output terminal B set on the side of the second layer are connected to the test points M1 and M2 on the device under test through external cables to obtain the data of the device under test.

[0049] Furthermore, the first layer includes a display module, which receives and displays data transmitted by the central control unit.

[0050] Ensure that the control unit can display the processed information on the display module.

[0051] Furthermore, a measurement method of a three-phase medical equipment leakage current measurement device performs the following steps:

[0052] SK. The leakage current measurement is divided into weighted mode and non-weighted mode. The central control unit controls the controlled transistor Q2 in the standard circuit to be turned on and the controlled transistor Q1 to be turned off for the weighted mode, and the controlled transistor Q2 to be turned off and the controlled transistor Q1 to be turned on for the non-weighted mode. When the weighted mode or / and non-weighted mode are selected, S1 to S5 are executed:

[0053] S1. The central control unit sends a signal to control the relay coils KM1, KM2, KM3, KM4, so that the relay switches K1, K2, K3, K4 are closed, the relay switch K5 is kept normally off, and the ammeters A1, A2, A3, A4 and the voltmeters V1, V2, V3, V4 as well as the voltmeter V and the ammeter A are measured;

[0054] S2. After completing the measurement of the last power-on state, control the relay coils KM1, KM2, KM3, and KM4 in sequence, disconnect the relay switches K1, K2, K3, and K4 one by one, disconnect only one relay switch at a time, and keep the other switches closed, and measure the ammeters A1, A2, A3, and A4 and the voltmeters V1, V2, V3, and V4 as well as the voltmeter V and the ammeter A in sequence;

[0055] S3. The central control unit controls the relay coils KM1, KM2, KM3, KM4, KM5 to turn on the relay switches K1, K2, K3, K4, K5, keep the relay K5 normally on, and measure the ammeters A1, A2, A3, A4 and the voltmeters V1, V2, V3, V4 as well as the voltmeter V and the ammeter A;

[0056] S4. After each measurement is completed, the relay coils KM1, KM2, KM3, and KM4 are controlled in sequence to disconnect the relay switches K1, K2, K3, and K4 one by one, and only one relay switch is disconnected at a time, while keeping the other switches closed, and the ammeters A1, A2, A3, and A4 and the voltmeters V1, V2, V3, and V4 as well as the voltmeter V and the ammeter A are measured in sequence;

[0057] S5. After completing all the measurements, the central control unit controls the coils KM1, KM2, KM3, KM4, and KM5 of the relay to disconnect the switches K1, K2, K3, K4, and K5 of the relay.

[0058] The test method makes the switch K5 of the relay in a normally-off state and the PE line between the grid power supply and the device under test normally off, and then turns on the switches K1, K2, K3, and K4 of the relay, which is the initial power-on state of the device under test; when the test is completed, the central control unit will send a signal to turn off the remaining relay switches except the relay switch K5, and after the leakage current test of each power-on state is completed, the disconnected relay needs to be turned on and the next relay needs to be turned off, and in the process of on-off control, it is ensured that only one relay except the relay switch K5 is in a disconnected state;

[0059] In each state, the currents A1, A2, A3 and V1, V2, V3 are calculated by the central control unit to obtain the current total power, and A1, A2, A3, A4 and V1, V2, V3, V4 and the calculated total power are displayed on the display screen in real time.

[0060] All power-on states of the device under test in leakage current mode are shown below:

[0061]

[0062] In the leakage current mode, the operator operates the test device as follows:

[0063] Connect the mains terminal group on the measuring device to the mains power supply, connect the terminal group of the device under test to the three-phase device under test, turn on the measuring device, the device completes the self-test, and the display prompts to select the measurement mode;

[0064] Select the mode by the mode switch on the device, and select the leakage current measurement mode;

[0065] Select the current leakage current detection mode. The leakage current detection mode is divided into weighted and non-weighted. Select the weighted mode, and the display will show the status information of the five terminals, the current leakage current detection mode and the leakage current value. Then press the function button to clear the current empty sampling data leakage.

[0066] Press the buttons corresponding to the terminals in sequence, the green indicator light turns on, the relay works, the device under test is in the first power-on state, and the leakage current in this state is measured. After the measurement is completed, the central control unit controls the on and off of the relays in sequence, so that the device under test is in different power-on states to complete the measurement.

[0067] Then select the non-weighted mode. After pressing it, the three-phase grid power supply will be automatically disconnected, and the device will enter the non-weighted leakage current measurement mode. The display screen will show the status information of the terminal, the current leakage current detection mode and the leakage current value. Then press the function button to clear the current empty sampling data leakage, and turn on all relays through the button to make the device under test in the first power-on state for measurement. After the measurement is completed, the central control unit controls the on and off of the relays in sequence, so that the device under test is in different power-on states to complete the measurement.

[0068] Example 2

[0069] When the operator measures power, the operator operates as follows:

[0070] After the mains power supply and the power supply of the device under test are connected, the three terminals on the measuring device corresponding to the three-phase medical device are connected to the three phase wires of the three-phase medical device, the measuring device is turned on, the device completes the self-test, and the display prompts to select the measurement mode, and the power measurement mode is selected;

[0071] Connect the network power supply, the indicator light in the off area on the device will light up, indicating that the relay is not working. Press the button corresponding to the indicator light to connect the relay. The indicator light corresponding to the off area will go out, and the indicator light in the on area will light up, indicating that the relay starts to work.

[0072] Press the function button on the device to select the power measurement mode: instantaneous value or average value. After selecting, press the start button to start the test.

[0073] After measuring for a period of time, press the end button to end the test, and the network power supply will be automatically disconnected. The red indicator light will light up. If the instantaneous value is selected, the instantaneous value within the measurement time will be printed out; if the average value is selected, the device will automatically calculate the average value within the measurement time, and then select print to output the power value.

[0074] The power-on status of the device under test connected to the test setup when measuring power is as follows:

[0075] Measurement Mode Relay K1 Relay K2 Relay K3 Relay K4 Relay K5 Power-on status Power Mode Pass Pass Pass Pass Pass State 0

[0076] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A three-phase medical equipment leakage current measuring device, characterized in that: The measuring device is provided with a relay, an ammeter, and a voltmeter between the live wire L1, live wire L2, live wire L3, and neutral wire N of the network power supply and the live wire L1, live wire L2, live wire L3, and neutral wire N of the corresponding device under test. The measuring device is provided with a relay between the ground wire PE of the network power supply and the ground wire PE of the corresponding device under test, wherein the switches K1, K2, K3, K4, and K5 of the relay are respectively connected in series between the live wire L1, live wire L2, live wire L3, neutral wire N, and ground wire PE of the network power supply and the live wire L1, live wire L2, live wire L3, neutral wire N, and ground wire PE of the corresponding device under test. The ammeters A1, A2, A3, and A4 are respectively connected in series between the live wire L1, live wire L2, live wire L3, and neutral wire N of the grid power supply and the live wire L1, live wire L2, live wire L3, and neutral wire N of the corresponding equipment under test, the voltmeters V1, V2, V3, and V4 are connected in parallel with the corresponding ammeters, the coils KM1, KM2, KM3, KM4, and KM5 of the relays are respectively controlled by the control ports Y1, Y2, Y3, Y4, and Y5 of the central control unit, and the voltmeters V1, V2, V3, and V4 and the corresponding ammeters feed data back to the central control unit; The measuring device also includes a standard circuit, whose input terminal A and output terminal B are respectively connected to the test points M1 and M2 of the device under test. The standard circuit has a voltmeter V and an ammeter A. The data measured by the voltmeter V and the ammeter A in the standard circuit are fed back to the central control unit.

2. A three-phase medical equipment leakage current measuring device according to claim 1, characterized in that: The standard circuit includes a resistor R1, a resistor R2, a capacitor C1, a switch 1, and a switch 2. The switch 2 and the resistor R1 and the capacitor C1 are connected in series to form a path N. The path N is connected in series with the ammeter A. The resistor R2 is connected in parallel with the path N. The voltmeter V is connected in parallel with the capacitor C1. The switch 2 and the resistor R1 are connected in series to form a path N1. The switch 1 is connected in parallel with the path N1. One end of the switch 2 is the input end A, and one end of the ammeter A is the output end B.

3. A three-phase medical equipment leakage current measuring device according to claim 2, characterized in that: The switch 1 and the switch 2 are controlled triodes.

4. A three-phase medical equipment leakage current measuring device according to claim 3, characterized in that: The controlled end of the controlled triode is connected to the central control unit to be controlled by the central control unit.

5. A three-phase medical equipment leakage current measuring device according to claim 1, characterized in that: The measuring device is divided into a first layer, a second layer and a third layer from top to bottom. The first layer and the second layer are fixedly installed, and the second layer and the third layer are hingedly installed.

6. A device for measuring leakage current of three-phase medical equipment according to claim 5, characterized in that: The third layer includes relays, terminals or terminal clamps, ammeters A1, A2, A3, A4 and voltmeters V1, V2, V3, V4. The terminals or terminal clamps are provided in two groups and are respectively arranged at the front end and the rear end of the test equipment. Each group of terminals or terminal clamps has five live wires L1, L2, L3, neutral wire N and ground wire PE corresponding to the grid power supply and the equipment under test. The terminals or terminal clamps are connected to the corresponding wiring. The switches K1, K2, K3, K4 of the relay and the ammeters A1, A2, A3, A4 are arranged in series between every two corresponding terminals. The switch K5 of the relay is arranged between the remaining corresponding terminals. The voltmeters V1, V2, V3, V4 are connected in parallel with the ammeters A1, A2, A3, A4 in a one-to-one correspondence.

7. The device for measuring leakage current of three-phase medical equipment according to claim 5, characterized in that: The second layer includes a central control unit and a standard circuit. An input terminal A and an output terminal B of the standard circuit are also arranged on the side of the second layer.

8. The device for measuring leakage current of three-phase medical equipment according to claim 5, characterized in that: The first layer includes a display module, which receives and displays data transmitted by the central control unit.

9. A measurement method of a three-phase medical equipment leakage current measurement device, characterized in that: Using any one of claims 1 to 8 of the three-phase medical equipment leakage current measuring device, perform the following steps: SK. The leakage current measurement is divided into weighted mode and non-weighted mode. The central control unit controls the controlled transistor Q2 in the standard circuit to be turned on and the controlled transistor Q1 to be turned off for the weighted mode, and the controlled transistor Q2 to be turned off and the controlled transistor Q1 to be turned on for the non-weighted mode. When the weighted mode or / and non-weighted mode are selected, S1 to S5 are executed: S1. The central control unit sends a signal to control the relay coils KM1, KM2, KM3, KM4, so that the relay switches K1, K2, K3, K4 are closed, the relay switch K5 is kept normally off, and the ammeters A1, A2, A3, A4 and the voltmeters V1, V2, V3, V4 as well as the voltmeter V and the ammeter A are measured; S2. After completing the measurement of the last power-on state, control the relay coils KM1, KM2, KM3, and KM4 in sequence, disconnect the relay switches K1, K2, K3, and K4 one by one, disconnect only one relay switch at a time, and keep the other switches closed, and measure the ammeters A1, A2, A3, and A4 and the voltmeters V1, V2, V3, and V4 as well as the voltmeter V and the ammeter A in sequence; S3. The central control unit controls the relay coils KM1, KM2, KM3, KM4, KM5 to turn on the relay switches K1, K2, K3, K4, K5, keep the relay K5 normally on, and measure the ammeters A1, A2, A3, A4 and the voltmeters V1, V2, V3, V4 as well as the voltmeter V and the ammeter A; S4. After each measurement is completed, the relay coils KM1, KM2, KM3, and KM4 are controlled in sequence to disconnect the relay switches K1, K2, K3, and K4 one by one, and only one relay switch is disconnected at a time, while keeping the other switches closed, and the ammeters A1, A2, A3, and A4 and the voltmeters V1, V2, V3, and V4 as well as the voltmeter V and the ammeter A are measured in sequence; S5. After completing all the measurements, the central control unit controls the coils KM1, KM2, KM3, KM4, and KM5 of the relay to disconnect the switches K1, K2, K3, K4, and K5 of the relay.

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