A loop resistance test system

Abstract

The present invention discloses a loop resistance testing system, including a main circuit and a control circuit. The main circuit includes a battery, a first inductor L1, a first capacitor C1, a second inductor L2, a second capacitor C2, a first switch circuit and a second switch circuit. The positive electrode of the battery is electrically connected to the first end of the first switch circuit via the first inductor L1, the second end of the first switch circuit is electrically connected to the first end of the second switch circuit and the first end of the first capacitor C1, the negative electrode of the battery is electrically connected to the third end of the first switch circuit and the second end of the first capacitor C1, the second end of the second switch circuit is electrically connected to the negative electrode of the battery via the second inductor L2, the third end of the second switch circuit is electrically connected to the negative electrode of the battery via the second capacitor C2, the two ends of the second capacitor C2 serve as positive and negative electrodes of the output, and the control circuit is electrically connected to the first switch circuit and the second switch circuit to control the on-off between the respective ends of the first switch circuit and the second switch circuit.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical testing, and in particular to a loop resistance testing system. Background Art

[0002] Circuit breaker loop resistance testing is a common requirement in existing power systems. This requires generating a low-voltage, high-current DC current of 100A, 200A, or even higher. Traditional loop resistance testers typically draw 220V AC power from a maintenance power source, using a step-down transformer and DC-DC converter to achieve a low-voltage, high-current output. This power supply solution is complex, bulky, and heavy, requiring long-distance wiring from a maintenance power box. This is not only inconvenient for outdoor mobile operation but also poses a risk of short-circuiting the maintenance power supply, posing a safety hazard of electric shock. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a loop resistance testing system which does not require long-distance wiring from a maintenance power box to draw power, is safe and reliable, and is easy to move and carry.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A loop resistance testing system includes a main circuit and a control circuit. The main circuit includes a battery, a first inductor L1, a first capacitor C1, a second inductor L2, a second capacitor C2, a first switch circuit and a second switch circuit. The positive electrode of the battery is electrically connected to the first end of the first switch circuit via the first inductor L1, the second end of the first switch circuit is electrically connected to the first end of the second switch circuit and the first end of the first capacitor C1, the negative electrode of the battery is electrically connected to the third end of the first switch circuit and the second end of the first capacitor C1, the second end of the second switch circuit is electrically connected to the negative electrode of the battery via the second inductor L2, and the third end of the second switch circuit is electrically connected to the negative electrode of the battery via the second capacitor C2. The two ends of the second capacitor C2 serve as positive and negative electrodes of the output. The control circuit is electrically connected to the first switch circuit and the second switch circuit to control the on-off between the respective ends of the first switch circuit and the second switch circuit.

[0006] Furthermore, the first switching circuit includes a first switching tube S1 and a first semiconductor device Q1, one end of the first switching tube S1 is electrically connected to the first end of the first switching circuit, and the other end is electrically connected to the third end of the first switching circuit, one end of the first semiconductor device Q1 is electrically connected to the first end of the first switching circuit, and the other end is electrically connected to the second end of the first switching circuit, the second switching circuit includes a second switching tube S2 and a second semiconductor device Q2, one end of the second switching tube S2 is electrically connected to the first end of the second switching circuit, and the other end is electrically connected to the second end of the second switching circuit, one end of the second semiconductor device Q2 is electrically connected to the second end of the second switching circuit, and the other end is electrically connected to the third end of the second switching circuit, and the control circuit is electrically connected to the control ends of the first switching tube S1 and the second switching tube S2.

[0007] Furthermore, the first semiconductor device Q1 and the second semiconductor device Q2 are both semiconductor switch tubes, and the control circuit is electrically connected to the control terminals of the first semiconductor device Q1 and the second semiconductor device Q2.

[0008] Furthermore, the first semiconductor device Q1 is a semiconductor diode, the second semiconductor device Q2 is a semiconductor switch tube, the anode of the first semiconductor device Q1 is electrically connected to the first end of the first switch circuit, the cathode is electrically connected to the second end of the first switch circuit, and the control circuit is electrically connected to the control end of the second semiconductor device Q2.

[0009] Furthermore, the first semiconductor device Q1 is a semiconductor switch tube, the second semiconductor device Q2 is a semiconductor diode, the anode of the second semiconductor device Q2 is electrically connected to the third end of the second switch circuit, the cathode is electrically connected to the second end of the second switch circuit, and the control circuit is electrically connected to the control end of the first semiconductor device Q1.

[0010] Furthermore, the first semiconductor device Q1 and the second semiconductor device Q2 are semiconductor diodes, the anode of the first semiconductor device Q1 is electrically connected to the first end of the first switching circuit, the cathode of the first semiconductor device Q1 is electrically connected to the second end of the first switching circuit, the anode of the second semiconductor device Q2 is electrically connected to the third end of the second switching circuit, and the cathode of the second semiconductor device Q2 is electrically connected to the second end of the second switching circuit.

[0011] Furthermore, it also includes a voltage sampling circuit and a current sampling circuit. The voltage sampling circuit collects the voltage vc1 across the first capacitor C1 and transmits it to the control circuit. The voltage sampling circuit collects the voltage vo across the second capacitor C1 and transmits it to the control circuit. The current sampling circuit collects the current io output by the main circuit and transmits it to the control circuit. The control circuit controls the on-off between each end of the first switch circuit and the second switch circuit according to the voltage vc1, the voltage vo and the current io to adjust the output voltage and the output current.

[0012] Furthermore, the ratio of the duty cycle D1 of the first switch tube S1 to the duty cycle D2 of the second switch tube S2 is calculated according to the following formula:

[0013] vo=vin*D2 / ((1-D1)*(1-D2));

[0014] Where vin is the voltage of the battery.

[0015] Furthermore, the output current io is used as a feedback signal, and the PI algorithm and the repetitive control algorithm are used in parallel to calculate and control the on-off between each end of the first switch circuit and the second switch circuit.

[0016] Furthermore, based on the output current io as a feedback signal, a PI algorithm is used to obtain a first voltage regulation signal, a repetitive control algorithm is used to obtain a second voltage regulation signal, the first voltage regulation signal and the second voltage regulation signal are weightedly added to obtain a third voltage regulation signal, and the on-off between each end of the second switch circuit is controlled according to the third voltage regulation signal; the first voltage regulation signal and the second voltage regulation signal are weighted to obtain a first capacitor voltage reference signal, and based on the first capacitor voltage reference signal and the first capacitor voltage vc1, a PI algorithm is used to control the on-off between each end of the first switch circuit.

[0017] The beneficial effects of the present invention are: a loop resistance test system, the test circuit is powered by a battery, there is no need to draw power from a long-distance wiring of a maintenance power box, it is safe and reliable, and easy to move and carry; using a switching power supply circuit, by controlling the switch tube to first allow the battery to charge the inductor and supercapacitor with a small current, and then allow the inductor and supercapacitor to discharge the resistance to be tested of the circuit breaker with a low voltage and a large current in a relatively short time; the test circuit has a built-in boost circuit, which only requires a lower input voltage, and the number of batteries required is small, and when the battery is discharged, there is a series inductor to limit the current, and the battery discharge current is small, which not only reduces the battery loss and increases the number of times the battery can be used, but also extends the overall service life of the battery; the test circuit does not use a transformer The device not only has low loss, but also greatly reduces the size and weight of the device. In addition, the use of a switching power supply circuit requires small and light components, simplifies the circuit, and reduces the cost. No resistors are used to limit current or divide voltage in the test circuit. Most of the battery energy is transferred to the circuit breaker resistor to be tested, resulting in high test circuit efficiency and low loss. A two-stage method is adopted. First, the battery charges the first capacitor C1 with a small current through the first stage, and then the first capacitor C1 discharges the circuit breaker resistor to be tested with a low voltage and a large current through the second stage. This avoids the battery directly discharging the circuit breaker resistor to be tested with a low voltage and a large current, greatly reduces the battery discharge current, reduces battery loss, increases the number of times the battery can be used, and extends the overall service life of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a circuit diagram of a loop resistance test according to an embodiment of the present invention.

[0019] Figure 2 This is a first switching state diagram of a loop resistance testing circuit according to an embodiment of the present invention.

[0020] Figure 3 This is a second switching state diagram of a loop resistance testing circuit according to an embodiment of the present invention.

[0021] Figure 4 This is a third switch state diagram of a loop resistance test circuit according to an embodiment of the present invention.

[0022] Figure 5 This is a fourth switch state diagram of a loop resistance test circuit according to an embodiment of the present invention.

[0023] Figure 6 This is a first test circuit diagram of a loop resistance test circuit according to an embodiment of the present invention.

[0024] Figure 7 This is a second test circuit diagram of a loop resistance test circuit according to an embodiment of the present invention.

[0025] Figure 8This is a third test circuit diagram of a loop resistance test circuit according to an embodiment of the present invention.

[0026] Figure 9 This is a fourth test circuit diagram of a loop resistance test circuit according to an embodiment of the present invention.

[0027] Figure 10 2 is a voltage sampling circuit diagram of an embodiment of the present invention.

[0028] Figure 11 2 is a current sampling circuit diagram of an embodiment of the present invention.

[0029] Figure 12 This is a circuit diagram of a single-chip processor according to an embodiment of the present invention.

[0030] Figure 13 This is a diagram of the first test circuit control method according to an embodiment of the present invention.

[0031] Figure 14 This is a diagram of a second test circuit control method according to an embodiment of the present invention.

[0032] Figure 15 This is a diagram of a third test circuit control method according to an embodiment of the present invention.

[0033] Figure 16 This is a diagram of a fourth test circuit control method according to an embodiment of the present invention.

[0034] Figure 17 This is a parallel composite control structure diagram of an embodiment of the present invention.

[0035] Figure 18 This is a resistance algorithm diagram of a loop resistance test circuit according to an embodiment of the present invention.

[0036] Figure 19 FIG. 4 is a first driving circuit diagram according to an embodiment of the present invention.

[0037] Figure 20 FIG. 4 is a diagram of a second driving circuit according to an embodiment of the present invention. DETAILED DESCRIPTION

[0038] To illustrate the technical content, achieved objectives and effects of the present invention in detail, the following description is given in conjunction with the embodiments and accompanying drawings.

[0039] Please refer to Figure 1-20A loop resistance testing system includes a main circuit and a control circuit, wherein the main circuit includes a battery, a first inductor L1, a first capacitor C1, a second inductor L2, a second capacitor C2, a first switch circuit, and a second switch circuit. The positive electrode of the battery is electrically connected to the first end of the first switch circuit via the first inductor L1, the second end of the first switch circuit is electrically connected to the first end of the second switch circuit and the first end of the first capacitor C1, the negative electrode of the battery is electrically connected to the third end of the first switch circuit and the second end of the first capacitor C1, the second end of the second switch circuit is electrically connected to the negative electrode of the battery via the second inductor L2, and the third end of the second switch circuit is electrically connected to the negative electrode of the battery via the second capacitor C2. The two ends of the second capacitor C2 serve as the positive and negative electrodes of the output, and the control circuit is electrically connected to the first switch circuit and the second switch circuit to control the on and off between the respective ends of the first switch circuit and the second switch circuit.

[0040] From the above description, it can be seen that the beneficial effects of the present invention are: a loop resistance test system, the test circuit is powered by a battery, there is no need to draw power from a long-distance wiring of the maintenance power box, it is safe and reliable, and easy to move and carry; using the switching power supply circuit, by controlling the switch tube to first allow the battery to charge the inductor and supercapacitor with a small current, and then allow the inductor and supercapacitor to discharge the circuit breaker resistance to be tested with a low voltage and a large current in a relatively short time; the test circuit has a built-in boost circuit, which only requires a lower input voltage, and the number of batteries required is small, and when the battery is discharged, there is a series inductor to limit the current, and the battery discharge current is small, which not only reduces the battery loss and increases the number of times the battery can be used, but also extends the overall service life of the battery; the test circuit has no The use of a transformer not only reduces losses but also greatly reduces the size and weight of the device. Furthermore, the use of a switching power supply circuit requires small and lightweight components, simplifies the circuit, and reduces cost. No resistors are used within the test circuit to limit current or divide voltage, and most of the battery energy is transferred to the circuit breaker resistor to be tested. The test circuit is highly efficient and has low losses. A two-stage method is employed, with the first stage enabling the battery to charge the first capacitor C1 with a small current, and the second stage enabling the first capacitor C1 to discharge the circuit breaker resistor to be tested with a low voltage and a high current. This avoids direct low-voltage, high-current discharge of the battery to the circuit breaker resistor to be tested, significantly reducing the battery discharge current, lowering battery loss, increasing the number of times the battery can be used, and extending the overall battery life.

[0041] Furthermore, the first switching circuit includes a first switching tube S1 and a first semiconductor device Q1, one end of the first switching tube S1 is electrically connected to the first end of the first switching circuit, and the other end is electrically connected to the third end of the first switching circuit, one end of the first semiconductor device Q1 is electrically connected to the first end of the first switching circuit, and the other end is electrically connected to the second end of the first switching circuit, the second switching circuit includes a second switching tube S2 and a second semiconductor device Q2, one end of the second switching tube S2 is electrically connected to the first end of the second switching circuit, and the other end is electrically connected to the second end of the second switching circuit, one end of the second semiconductor device Q2 is electrically connected to the second end of the second switching circuit, and the other end is electrically connected to the third end of the second switching circuit, and the control circuit is electrically connected to the control ends of the first switching tube S1 and the second switching tube S2.

[0042] It can be seen from the above description that the specific structures of the first switch circuit and the second switch circuit are given to achieve the control of on-off between the terminals.

[0043] Furthermore, the first semiconductor device Q1 and the second semiconductor device Q2 are both semiconductor switch tubes, and the control circuit is electrically connected to the control terminals of the first semiconductor device Q1 and the second semiconductor device Q2.

[0044] It can be seen from the above description that the first main circuit loop structure is realized.

[0045] Furthermore, the first semiconductor device Q1 is a semiconductor diode, the second semiconductor device Q2 is a semiconductor switch tube, the anode of the first semiconductor device Q1 is electrically connected to the first end of the first switch circuit, the cathode is electrically connected to the second end of the first switch circuit, and the control circuit is electrically connected to the control end of the second semiconductor device Q2.

[0046] It can be seen from the above description that the second main circuit loop structure is realized.

[0047] Furthermore, the first semiconductor device Q1 is a semiconductor switch tube, the second semiconductor device Q2 is a semiconductor diode, the anode of the second semiconductor device Q2 is electrically connected to the third end of the second switch circuit, the cathode is electrically connected to the second end of the second switch circuit, and the control circuit is electrically connected to the control end of the first semiconductor device Q1.

[0048] From the above description, it can be seen that the third main circuit loop structure is realized.

[0049] Furthermore, the first semiconductor device Q1 and the second semiconductor device Q2 are semiconductor diodes, the anode of the first semiconductor device Q1 is electrically connected to the first end of the first switching circuit, the cathode of the first semiconductor device Q1 is electrically connected to the second end of the first switching circuit, the anode of the second semiconductor device Q2 is electrically connected to the third end of the second switching circuit, and the cathode of the second semiconductor device Q2 is electrically connected to the second end of the second switching circuit.

[0050] From the above description, it can be seen that the fourth main circuit loop structure is realized.

[0051] Furthermore, it also includes a voltage sampling circuit and a current sampling circuit. The voltage sampling circuit collects the voltage vc1 across the first capacitor C1 and transmits it to the control circuit. The voltage sampling circuit collects the voltage vo across the second capacitor C1 and transmits it to the control circuit. The current sampling circuit collects the current io output by the main circuit and transmits it to the control circuit. The control circuit controls the on-off between each end of the first switch circuit and the second switch circuit according to the voltage vc1, the voltage vo and the current io to adjust the output voltage and the output current.

[0052] From the above description, it can be seen that the output voltage and current are precisely adjusted according to the sampled voltage and the sampled current, thereby realizing multi-variable automatic adjustment, faster adjustment speed and higher accuracy.

[0053] Furthermore, the ratio of the duty cycle D1 of the first switch tube S1 to the duty cycle D2 of the second switch tube S2 is calculated according to the following formula:

[0054] vo=vin*D2 / ((1-D1)*(1-D2));

[0055] Where vin is the voltage of the battery.

[0056] It can be seen from the above description that the output voltage value is regulated.

[0057] Furthermore, the output current io is used as a feedback signal, and the PI algorithm and the repetitive control algorithm are used in parallel to calculate and control the on-off between each end of the first switch circuit and the second switch circuit.

[0058] It can be seen from the above description that the output current value is regulated.

[0059] Furthermore, based on the output current io as a feedback signal, a PI algorithm is used to obtain a first voltage regulation signal, a repetitive control algorithm is used to obtain a second voltage regulation signal, the first voltage regulation signal and the second voltage regulation signal are weightedly added to obtain a third voltage regulation signal, and the on-off between each end of the second switch circuit is controlled according to the third voltage regulation signal; the first voltage regulation signal and the second voltage regulation signal are weighted to obtain a first capacitor voltage reference signal, and based on the first capacitor voltage reference signal and the first capacitor voltage vc1, a PI algorithm is used to control the on-off between each end of the first switch circuit.

[0060] From the above description, it can be seen that in the transient process, the PI regulator is mainly used for regulation, so as to achieve a faster response speed to the circuit breaker resistance current io to be measured; in the steady state, the repetitive controller is mainly used for regulation, so as to achieve error-free tracking of the circuit breaker resistance current io to be measured.

[0061] The present invention is applied to testing the internal resistance of each internal electrical circuit.

[0062] Please refer to Figure 1-20 , embodiment 1 of the present invention is:

[0063] A loop resistance testing system includes a main circuit and a control circuit; the main circuit includes a battery, a first inductor L1, a first switching tube S1, a first semiconductor device Q1, a first capacitor C1, a second switching tube S2, a second inductor L2, a second semiconductor device Q2, a second capacitor C2, and a circuit breaker resistance to be measured; the control circuit includes a drive circuit, a voltage sampling circuit, a current sampling circuit, and a single-chip processor circuit; the drive circuit includes a first drive circuit and a second drive circuit.

[0064] The positive electrode of the battery is electrically connected to the first end of the first inductor L1; the second end of the first inductor L1 is electrically connected to the first end of the first switch tube S1 and the first end of the first semiconductor device Q1; the second end of the first semiconductor device Q1 is electrically connected to the first end of the first capacitor C1 and the first end of the second switch tube S2; the second end of the second switch tube S2 is electrically connected to the first end of the second inductor L2 and the first end of the second semiconductor device Q2; the second end of the second semiconductor device Q2 is electrically connected to the first end of the second capacitor C2 and the first end of the resistor to be measured of the circuit breaker; the negative electrode of the battery is electrically connected to the second end of the first switch tube S1, the first end of the first inductor L1 and the first end of the first semiconductor device Q1. The second end of the capacitor C1, the second end of the second inductor L2, the second end of the second capacitor C2 and the second end of the resistor to be measured of the circuit breaker are electrically connected; the voltage sampling circuit is electrically connected to the first capacitor C1 and the single-chip processor circuit; the voltage sampling circuit is electrically connected to the second capacitor C2 and the single-chip processor circuit; the current sampling circuit is electrically connected to the second end of the resistor to be measured of the circuit breaker and the single-chip processor circuit; the drive circuit is electrically connected to the single-chip processor circuit, the first switch tube S1 and the first semiconductor device Q1; the drive circuit is electrically connected to the single-chip processor circuit, the second switch tube S2 and the second semiconductor device Q2.

[0065] The test circuit has four switching states, such as Figure 2 As shown, in the first switching state, the first switch tube S1 is turned on, the first semiconductor device Q1 is turned off, the battery, the first inductor L1 and the first switch tube S1 form a conductive loop, the voltage vL1 across the first inductor L1 is equal to the battery voltage vin, that is, vL1 = vin and is greater than zero, the first inductor L1 stores energy, and the current iL1 of the first inductor L1 increases, which is equivalent to the battery charging the first inductor L1;

[0066] like Figure 3 As shown, in the second switching state, the first semiconductor device Q1 is turned on, the first switch tube S1 and the second switch tube are turned off, and the battery, the first inductor L1, the first semiconductor device Q1 and the first capacitor C1 form a conductive loop. The voltage vL1 across the first inductor L1 is equal to the negative voltage vC1 of the first capacitor C1 minus the battery voltage vin, that is, vL1 = -(vC1-vin) and is less than zero. The first inductor L1 releases energy, the current iL1 of the first inductor L1 decreases, and the current iC1 flowing through the first capacitor C1 is greater than zero. The first capacitor C1 stores energy, which is equivalent to the battery and the first inductor L1 charging the first capacitor C1 together.

[0067] like Figure 4As shown, in the third switching state, the second switch tube S2 is turned on, the second semiconductor device Q2 is turned off, the first capacitor C1, the second switch tube S2 and the second inductor L2 form a conductive loop, the current iC1 flowing through the first capacitor C1 is less than zero, the first capacitor C1 releases energy, the voltage vL2 across the second inductor L2 is equal to the voltage vC1 of the first capacitor C1, that is, vL2 = vC1 and is greater than zero, the second inductor L2 stores energy, and the current iL2 of the second inductor L2 increases, which is equivalent to the first capacitor C1 charging the second inductor L2; the second capacitor C2 and the circuit breaker resistor to be tested form a conductive loop, the current iC2 flowing through the second capacitor C2 is less than zero, the second capacitor C2 releases energy, which is equivalent to the second capacitor C2 supplying power to the circuit breaker resistor to be tested;

[0068] like Figure 5 As shown, in the fourth switching state, the second semiconductor device Q2 is turned on, the second switch tube S2 is turned off, the second inductor L2, the second semiconductor device Q2 and the second capacitor C2 form a conductive loop, the voltage vL2 across the second inductor L2 is equal to the negative voltage vo of the second capacitor C2, that is, vL2 = -vo and is less than zero, the second inductor L2 releases energy, the current iL2 of the second inductor L2 decreases, the current iC2 flowing through the second capacitor C2 is greater than zero, and the second capacitor C2 stores energy, which is equivalent to the second inductor L2 charging the second capacitor C2; the second inductor L2, the second semiconductor device Q2 and the circuit breaker resistor to be tested form a conductive loop, the voltage vL2 across the second inductor L2 is equal to the negative voltage vo of the second capacitor C2, that is, vL2 = -vo and is less than zero, the second inductor L2 releases energy, the current iL2 of the second inductor L2 decreases, which is equivalent to the second inductor L2 supplying power to the circuit breaker resistor to be tested.

[0069] The first and second switching states are equivalent to the charging states of the test circuit, and the battery charges the first capacitor C1 by controlling the first switch tube S1 and the first semiconductor device Q1; the third and fourth switching states are equivalent to the discharging states of the test circuit, and the first capacitor C1 supplies power to the resistance to be tested of the circuit breaker by controlling the second switch tube S2 and the second semiconductor device Q2.

[0070] When performing loop resistance testing, the voltage of the first capacitor C1 is vC1 = vin / (1-D1)

[0071] , where D1 (0≤D1≤1) is the duty cycle of the first switch tube S1; the voltage of the second capacitor C2 is vo=vC1*D2 / (1-D2), where D2 (0≤D2≤1) is the duty cycle of the second switch tube S2; the voltage of the second capacitor C2, i.e. the output voltage, is vo=vin*D2 / ((1-D1)*(1-D2)). Therefore, the circuit can control the output voltage vo by adjusting the duty cycle D1 of the first switch tube S1 and the duty cycle D2 of the second switch tube S2, thereby realizing the test circuit outputting low voltage and high current.

[0072] When performing a loop resistance test, the circuit has four operating modes; the first operating mode consists of the first switching state and the third switching state; the second operating mode consists of the first switching state and the fourth switching state; the third operating mode consists of the second switching state and the third switching state; and the fourth operating mode consists of the second switching state and the fourth switching state.

[0073] Specifically, if Figure 6 As shown, in the first test circuit, a semiconductor switch tube is selected as the first semiconductor device Q1, and a semiconductor switch tube is selected as the second semiconductor device Q2; the single-chip processor circuit receives the signal v1 of the voltage vc1 of the first capacitor C1 after passing through the voltage sampling circuit, the signal v2 of the voltage vc2 of the second capacitor C2 after passing through the voltage sampling circuit, and the signal i1 of the current io of the circuit breaker resistance to be measured after passing through the current sampling circuit, and outputs control signals vd1, vd2, vd3 and vd4 respectively through the internal program PI algorithm and the repetitive control algorithm; vd1 and vd2 output drive signals vgs1 and vgs2 after passing through the first drive circuit and are transmitted to the first switch tube S1 and the first semiconductor device Q1 to control them to be turned on or off; vd3 and vd4 output drive signals vgs3 and vgs4 after passing through the first drive circuit and are transmitted to the second switch tube S2 and the second semiconductor device Q2 to control them to be turned on or off, thereby enabling the circuit to output low voltage and high current, and using the effective value algorithm and the division algorithm to calculate the resistance value to be measured of the circuit breaker;

[0074] like Figure 7As shown, in the second test circuit, a semiconductor diode is selected as the first semiconductor device Q1, and a semiconductor switch tube is selected as the second semiconductor device Q2; the single-chip processor circuit receives the signal v1 of the voltage vc1 of the first capacitor C1 after passing through the voltage sampling circuit, the signal v2 of the voltage vc2 of the second capacitor C2 after passing through the voltage sampling circuit, and the signal i1 of the current io of the circuit breaker resistance to be measured after passing through the current sampling circuit, and outputs control signals vd1, vd3 and vd4 respectively through the internal program PI algorithm and the repetitive control algorithm; vd1 outputs the driving signal vgs1 after passing through the second driving circuit and transmits it to the first switch tube S1 to control it to be turned on or off, and vd3 and vd4 output the driving signals vgs3 and vgs4 after passing through the first driving circuit and transmit them to the second switch tube S2 and the second semiconductor device Q2 to control them to be turned on or off, thereby enabling the circuit to output low voltage and high current, and calculate the resistance value of the circuit breaker to be measured using the effective value algorithm and the division algorithm;

[0075] like Figure 8 As shown, in the third test circuit, a semiconductor switch tube is selected as the first semiconductor device Q1, and a semiconductor diode is selected as the second semiconductor device Q2; the single-chip processor circuit receives the signal v1 of the voltage vc1 of the first capacitor C1 after passing through the voltage sampling circuit, the signal v2 of the voltage vc2 of the second capacitor C2 after passing through the voltage sampling circuit, and the signal i1 of the current io of the circuit breaker resistance to be measured after passing through the current sampling circuit, and outputs control signals vd1, vd2, and vd3 respectively through the internal program PI algorithm and the repetitive control algorithm; vd1 and vd2 output drive signals vgs1 and vgs2 after passing through the first drive circuit and are transmitted to the first switch tube S1 and the first semiconductor device Q1 to control them to be turned on or off, and vd3 outputs drive signal vgs3 after passing through the second drive circuit and is transmitted to the second switch tube S2 to control it to be turned on or off, thereby enabling the circuit to output low voltage and high current, and calculate the resistance value of the circuit breaker to be measured using the effective value algorithm and the division algorithm;

[0076] like Figure 9As shown, in the fourth test circuit, a semiconductor diode is selected as the first semiconductor device Q1, and a semiconductor diode is selected as the second semiconductor device Q2; the single-chip processor circuit receives the signal v1 of the voltage vc1 of the first capacitor C1 after passing through the voltage sampling circuit, the signal v2 of the voltage vc2 of the second capacitor C2 after passing through the voltage sampling circuit, and the signal i1 of the current io of the circuit breaker resistance to be measured after passing through the current sampling circuit, and outputs control signals vd1 and vd3 respectively through the internal program PI algorithm and the repetitive control algorithm; vd1 outputs the drive signal vgs1 after passing through the second drive circuit and is transmitted to the first switch tube S1 to control its conduction or shutdown, and vd3 outputs the drive signal vgs3 after passing through the second drive circuit and is transmitted to the second switch tube S2 to control its conduction or shutdown, thereby enabling the test circuit to output low voltage and high current, and calculate the circuit breaker resistance to be measured using the effective value algorithm and the division algorithm.

[0077] like Figure 10 As shown, the sampling signal vc1 of the first capacitor C1 and the voltage sampling signal vo of the second capacitor C2 are amplified and then output to the single chip processor circuit, such as Figure 11 As shown, the sampling signal io of the output current is collected by the Hall sensor and then amplified and output to the single chip processor circuit.

[0078] When performing a loop resistance test, Figure 12 MCU processor circuit receiving Figure 10 The signal v1 after the voltage vc1 of the first capacitor C1 passes through the voltage sampling circuit, the signal v2 after the voltage vc2 of the second capacitor C2 passes through the voltage sampling circuit, and Figure 11 The circuit breaker resistance current io to be measured is signaled by the current sampling circuit i1; Figure 13 、 14 , 15 and 16 are calculated by internal program PI algorithm and repetitive control algorithm, and output control signals vd1, vd2, vd3 and vd4 respectively, and Figure 18 and 19 The driving circuit outputs driving signals vgs1, vgs2, vgs3 and vgs4 respectively, which are transmitted to the first switch tube S1, the first semiconductor device Q1, the second switch tube S2 and the second semiconductor device Q2 respectively, and control the first switch tube S1, the first semiconductor device Q1, the second switch tube S2 and the second semiconductor device Q2 to be turned on or off respectively, so that the test circuit can output low voltage and high current, and use the following methods: Figure 18 The effective value algorithm and division algorithm shown calculate the resistance value of the circuit breaker to be measured.

[0079] like Figure 17As shown, the circuit breaker resistance current io to be measured adopts a composite control method in which a PI algorithm and a repetitive control algorithm are connected in parallel. During the transient process, due to the fast response speed of the PI controller, the PI regulator is mainly used for regulation, thereby achieving a faster response speed for the circuit breaker resistance current io to be measured. In the steady state, due to the error-free tracking capability of the repetitive controller, the repetitive controller is mainly used for regulation, thereby achieving error-free tracking of the circuit breaker resistance current io to be measured. The sum of the output signals of the PI regulator and the repetitive controller is modulated to obtain a drive signal for the second switch tube S2 and the second semiconductor device Q2, and is simultaneously used as a reference signal for the first capacitor voltage, thereby ensuring that the test circuit achieves a fast and accurate output of a low-voltage and high-current.

[0080] The first capacitor C1 and the second capacitor C2 are supercapacitors, which have the advantages of high power density, high energy conversion efficiency and fast high current charging and discharging speed. They can achieve low voltage and high current discharge of the circuit breaker resistance to be tested in a relatively short time.

[0081] Compared with the traditional single-stage circuit, the test circuit adopts a two-stage method. First, the battery charges the first capacitor C1 with a small current through the first stage, and then the first capacitor C1 discharges the circuit breaker resistor to be tested with a low voltage and a large current through the second stage. This avoids the battery directly discharging the circuit breaker resistor to be tested with a low voltage and a large current, greatly reducing the battery discharge current. This not only reduces battery loss and increases the number of times the battery can be used, but also extends the overall service life of the battery.

[0082] Compared with the traditional single-stage circuit, the test circuit adopts a multi-variable closed-loop feedback control method. When automatically adjusting the current io of the circuit breaker resistance to be tested, it can also automatically adjust the voltage vc1 of the first capacitor C1, realizing multi-variable automatic adjustment, so the adjustment speed is faster and the accuracy is higher.

[0083] like Figure 19 As shown, the first driving circuit includes a first driving chip, which receives the signal of the single chip processing circuit and drives the first semiconductor device Q1 and the first switch tube S1; Figure 20 As shown, the second driving circuit includes a second driving chip, which receives the signal of the single chip processing circuit and drives the first semiconductor device Q2 and the first switch tube S2

[0084] In this example, the battery is a 6V polymer lithium battery; the first capacitor C1 and the second capacitor C2 are 2.7V large-cell supercapacitors with a discharge current of up to 500A; the first switch tube S1, the second switch tube S2 and the semiconductor switch tube are N-type MOS tubes with a maximum current of 500A; the semiconductor diode is a diode with a maximum current of 500A; the voltage sampling circuit chip model is the operational amplifier MCP60; the current sampling circuit chip model is the Hall current sensor ACS730 and the operational amplifier MCP60; the microcontroller processor chip model is DSPIC33FJ; the first drive unit chip model is SI8233; the second drive unit chip model is SI8271.

[0085] In summary, the present invention provides a loop resistance test system, in which the test circuit is powered by a battery, and there is no need to draw power from a maintenance power box over a long distance. The system is safe, reliable, and easy to move and carry. The switching power supply circuit is used to control the switch tube to first allow the battery to charge the inductor and supercapacitor with a small current, and then allow the inductor and supercapacitor to discharge the resistance to be tested of the circuit breaker with a low voltage and a large current in a relatively short time; the test circuit has a built-in boost circuit, which only requires a lower input voltage, and a smaller number of batteries are required. When the battery is discharged, there is a series inductor to limit the current, and the battery discharge current is small, which not only reduces the battery loss and increases the number of times the battery can be used, but also extends the overall service life of the battery. The test circuit does not use a transformer The device not only has low loss, but also greatly reduces the size and weight of the device. In addition, the use of a switching power supply circuit requires small and light components, simplifies the circuit, and reduces the cost. No resistors are used to limit current or divide voltage in the test circuit. Most of the battery energy is transferred to the circuit breaker resistor to be tested. The test circuit has high efficiency and low loss. A two-stage method is adopted. First, the battery charges the first capacitor C1 with a small current through the first stage, and then the first capacitor C1 is discharged with a low voltage and a large current to the circuit breaker resistor to be tested through the second stage. This avoids the battery directly discharging with a low voltage and a large current to the circuit breaker resistor to be tested, greatly reduces the battery discharge current, reduces battery loss, increases the number of times the battery can be used, and extends the overall service life of the battery.

[0086] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's description and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A loop resistance test system, characterized in that: The main circuit includes a battery, a first inductor L1, a first capacitor C1, a second inductor L2, a second capacitor C2, a first switch circuit, and a second switch circuit; The positive electrode of the battery is electrically connected to the first end of the first switch circuit via the first inductor L1, the second end of the first switch circuit is electrically connected to the first end of the second switch circuit and the first end of the first capacitor C1, the negative electrode of the battery is electrically connected to the third end of the first switch circuit and the second end of the first capacitor C1, the second end of the second switch circuit is electrically connected to the negative electrode of the battery via the second inductor L2, and the third end of the second switch circuit is electrically connected to the negative electrode of the battery via the second capacitor C2. The two ends of the second capacitor C2 serve as the positive and negative electrodes of the output, and the control circuit is electrically connected to the first switch circuit and the second switch circuit to control the connection and disconnection between the respective ends of the first switch circuit and the second switch circuit; The system further includes a voltage sampling circuit and a current sampling circuit. The voltage sampling circuit collects a voltage vc1 across the first capacitor C1 and transmits it to the control circuit. The voltage sampling circuit collects a voltage vo across the second capacitor C1 and transmits it to the control circuit. The current sampling circuit collects a current io output by the main circuit and transmits it to the control circuit. The control circuit controls the on-off between each end of the first switch circuit and the second switch circuit according to the voltage vc1, the voltage vo, and the current io to adjust the output voltage and the output current. Based on the output current io as a feedback signal, the PI algorithm and the repetitive control algorithm are used in parallel to calculate and control the on-off between each end of the first switching circuit and the second switching circuit; Based on the output current io as a feedback signal, a PI algorithm is used to obtain a first voltage regulation signal, and a repetitive control algorithm is used to obtain a second voltage regulation signal. The first voltage regulation signal and the second voltage regulation signal are weightedly added to obtain a first capacitor voltage reference signal. The on-off between each end of the second switch circuit is controlled according to the first capacitor voltage reference signal. Based on the first capacitor voltage reference signal and the first capacitor voltage vc1, a PI algorithm is used to control the on-off between each end of the first switch circuit.

2. A loop resistance testing system according to claim 1, characterized in that: The first switching circuit includes a first switching tube S1 and a first semiconductor device Q1, one end of the first switching tube S1 is electrically connected to the first end of the first switching circuit, and the other end is electrically connected to the third end of the first switching circuit. One end of the first semiconductor device Q1 is electrically connected to the first end of the first switching circuit, and the other end is electrically connected to the second end of the first switching circuit. The second switching circuit includes a second switching tube S2 and a second semiconductor device Q2, one end of the second switching tube S2 is electrically connected to the first end of the second switching circuit, and the other end is electrically connected to the second end of the second switching circuit. One end of the second semiconductor device Q2 is electrically connected to the second end of the second switching circuit, and the other end is electrically connected to the third end of the second switching circuit. The control circuit is electrically connected to the control ends of the first switching tube S1 and the second switching tube S2.

3. A loop resistance testing system according to claim 2, characterized in that: The first semiconductor device Q1 and the second semiconductor device Q2 are both semiconductor switch tubes, and the control circuit is electrically connected to the control terminals of the first semiconductor device Q1 and the second semiconductor device Q2.

4. A loop resistance testing system according to claim 2, characterized in that: The first semiconductor device Q1 is a semiconductor diode, the second semiconductor device Q2 is a semiconductor switch tube, the anode of the first semiconductor device Q1 is electrically connected to the first end of the first switch circuit, the cathode is electrically connected to the second end of the first switch circuit, and the control circuit is electrically connected to the control end of the second semiconductor device Q2.

5. A loop resistance testing system according to claim 2, characterized in that: The first semiconductor device Q1 is a semiconductor switch tube, the second semiconductor device Q2 is a semiconductor diode, the anode of the second semiconductor device Q2 is electrically connected to the third end of the second switch circuit, and the cathode is electrically connected to the second end of the second switch circuit. The control circuit is electrically connected to the control end of the first semiconductor device Q1.

6. A loop resistance testing system according to claim 2, characterized in that: The first semiconductor device Q1 and the second semiconductor device Q2 are semiconductor diodes, the anode of the first semiconductor device Q1 is electrically connected to the first end of the first switching circuit, the cathode of the first semiconductor device Q1 is electrically connected to the second end of the first switching circuit, the anode of the second semiconductor device Q2 is electrically connected to the third end of the second switching circuit, and the cathode of the second semiconductor device Q2 is electrically connected to the second end of the second switching circuit.

7. The loop resistance testing system according to claim 1, characterized in that: The ratio of the duty cycle D1 of the first switch S1 to the duty cycle D2 of the second switch S2 is calculated according to the following formula: vo=vin*D2 / (D1*(1-D2)); Where vin is the voltage of the battery.

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