A debugging tool and debugging method for open-loop debugging of a voltage stabilization point of an electrically excited generator power supply system

Abstract

The application discloses a debugging tool and a debugging method for open-loop debugging of a voltage stabilization point of an electric excitation generator power supply system. The method determines the resistance value of a debugging resistor through calculation by testing the reference voltage and the sampling voltage of a voltage regulator in a voltage regulator. The method improves the debugging efficiency, shortens the debugging time of the voltage stabilization point from about 12 minutes per unit in the original debugging method to less than 2 minutes, avoids welding a potentiometer at the position of the debugging resistor, then unwelding the potentiometer, and finally replacing the fixed resistor in the "welding-unwelding-welding" process, and improves the reliability of the welding pad.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of generators, and particularly relates to a debugging tool and a debugging method for open-loop debugging of a voltage stabilization point of a power supply system of an electrically excited generator. BACKGROUND

[0002] In a generator power supply system composed of an excitation generator and an automatic voltage regulator, the voltage stabilization point of the voltage regulator determines the output voltage of the power supply system. Due to the manufacturing differences of the parameters of the components in the voltage regulator, the voltage stabilization point of the voltage regulator after the completion of the electrical installation generally cannot meet the technical requirements, so the voltage stabilization point needs to be debugged. The output voltage of the generator power supply system is a closed-loop parameter when the generator and the voltage regulator are working, and theoretically, the debugging needs to be performed in a closed-loop state. The closed-loop debugging needs to be performed on a high-speed driving table, which will bring about problems such as high cost, insecurity to personnel, products (the generator and the voltage regulator) and equipment (the high-speed table and the test equipment), so in practice, open-loop debugging is adopted instead of closed-loop debugging.

[0003] The excitation generator has two types of single-direction excitation and double-direction excitation, and there are two types of single-direction excitation voltage regulator and double-direction excitation voltage regulator. When the two types of voltage regulators are working in an open-loop state, the polarity (or level) of the output voltage will be reversed when the input voltage reaches the voltage stabilization point. This feature can be used to perform open-loop debugging of the voltage stabilization point of the voltage regulator.

[0004] The existing debugging method is as follows: a potentiometer is welded at the debugging resistor position of a sampling circuit by using a direct-current power supply as input and a resistor as output load, the input voltage is slowly increased, the change of the output voltage is observed, and when the polarity (or level) of the output voltage is reversed, the input voltage at this time is the voltage stabilization point of the voltage regulator in the current state. When the observed voltage stabilization point is higher than the required technical index, the resistance value of the potentiometer is increased, otherwise, the resistance value of the potentiometer is decreased, then the voltage stabilization point is observed, and the potentiometer is adjusted ……, and this is repeated until the required voltage stabilization point is obtained, and then the potentiometer is welded, and a fixed resistor with the same resistance value is replaced. This is a trial-and-error debugging method (which can be called trial-and-error method), and the debugging efficiency is low, and the welding pad needs to undergo the processes of welding, unwelding and re-welding, which has an impact on the reliability of the welding pad.

[0005] Therefore, it is urgent to provide a simple and easy method for determining the debugging resistance value through testing and calculation, which does not need to perform the operations of welding, unwelding and re-welding on the welding pad of the debugging resistor, and reduces the complexity of the debugging work. SUMMARY

[0006] To solve the above technical problems, the present application provides a debugging tool and a debugging method for open-loop debugging of a voltage stabilization point of a power supply system of an electrically excited generator.

[0007] The present invention is achieved through the following technical solutions.

[0008] This invention provides an open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system. The fixture includes a sampling circuit and a testing fixture. The sampling circuit is installed in the automatic voltage regulator of the generator power supply system. The sampling circuit includes resistors R1-R3, with one end of resistor R1 connected to the generator output voltage V. e One end of R5 is connected to one end of R1, and the other end of R2 is grounded; one end of R3 is connected to the other end of R1, and the other end of R3 is grounded. R3 is the debugging resistor to be tested. The automatic voltage regulator also includes a PWM control circuit, which contains a voltage regulator. The voltage regulator includes resistors R4-R6, operational amplifier U1, and capacitor C1. One end of resistor R4 is connected to the other end of R1, and the other end is connected to the negative input terminal of operational amplifier U1. One end of R5 is connected to the reference voltage V. r One end of the multimeter is connected to the positive input terminal of the operational amplifier U1, and the other end of the multimeter is connected to one end of the capacitor C1. The other end of the capacitor C1 is connected to one end of the resistor R6, and the other end of the resistor R6 is connected to the negative input terminal of the operational amplifier U1. The test fixture includes a switch K and a test resistor R301. One end of the switch K is connected to the positive terminal and probe of the multimeter, and the other end is connected to one end of the resistor R301. The other end of the resistor R301 is connected to the negative terminal of the power supply and the negative terminal of the multimeter.

[0009] A debugging method for an open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system, wherein the resistance of the debugging resistor R3 to be tested is R x During debugging, R3 was not connected to the sampling circuit. A test fixture was used for debugging, specifically including the following steps:

[0010] Step 1, convert the generator's input voltage V in Adjust to the voltage regulator point V w Set the voltage to 0.5V, take the resistance value of resistor 301 as the design nominal value of resistor R3 to be debugged, install the debugging fixture, and connect the other end of resistor R301 to the negative terminal of the power supply.

[0011] Step 2: With switch K open, use the probe of the debugging fixture to contact one end of resistor R5, and measure the reference voltage V using the multimeter reading. r The value;

[0012] Step 3: With switch K open, use the probe of the debugging fixture to contact the end where resistor R4 and R1 are connected. Measure the sampling voltage V of resistor R2 without resistor R301 connected in parallel using a multimeter. f0 The value;

[0013] Step 4, close switch K, use the probe of the debugging tool to contact the end of resistance R4 connected with R1, according to the reading of the multimeter, measure the sampling voltage V f3 when resistance R2 is in parallel with resistance R301;

[0014] Step 5, calculate the resistance value of R X according to the formula , wherein R3 takes the design nominal value;

[0015] Step 6, take the resistance closest to the resistance value of R X calculated in step 5 as the debugging resistance R3 connected to the sampling circuit in actual application.

[0016] Further, in step 5, the derivation process of the formula includes the following steps:

[0017] Step 501, when the generator output voltage V e is equal to the voltage V w at the stable voltage point, the sampling signal voltage V f is equal to the reference voltage V r , the PWM controller outputs a stable degree pulse width, generates a stable excitation current, and the closed-loop system is in a dynamic balance state, at this time , let the voltage division ratio of the sampling circuit be k (i.e. ), then:

[0018] …………………………………(1)

[0019] Step 502, let the resistance value of the debugging resistance R3 to be solved be R x , and the voltage V w at the stable voltage point meets the technical index requirements of the product, according to formula (1), we can get:

[0020] …………(2)

[0021] In the formula:

[0022] V fx : the sampling voltage when the resistance value of the debugging resistance is R x ; V w : the voltage at the stable voltage point required by the product technical index (known); V r : the reference voltage, which can be tested (known); R1, R2: the values are unknown (the actual value is difficult to measure online); R x : the parameter to be solved;

[0023] Step 503, in order to solve Rx, two tests need to be performed in two states, and two equations are added: R301 is not installed when not debugging, and the input voltage The sampling voltage is:

[0024] (3)

[0025] V f0 : The sampling voltage when R301 is not installed, which can be measured (known);

[0026] A resistor R301 with a known resistance is connected in parallel across R2. The resistance can be the nominal value of R3 in the specific design, and the input voltage The sampling voltage is:

[0027] (4)

[0028] V f3 : The sampling voltage after connecting R301 in parallel, which can be measured (known); R3: the nominal value of the design (known);

[0029] Step 504, solve equations (2), (3), and (4) simultaneously to get:

[0030] (5)

[0031] R x is the resistance value of the debugging resistor required.

[0032] Further, in step 1, the output current of the generator power supply needs to be adjusted to the specified value in the debugging rules.

[0033] Further, in step 5, if Rx is calculated to be negative, replace R2 with a larger resistance and repeat steps 1-5 until R x is positive.

[0034] Further, in steps 2-3, when testing V r , V f0 , and V f3 , the input voltage V e must be kept constant.

[0035] Further, in the test tool, the clip is used to connect the resistor R301 to the negative terminal of the power supply.

[0036] Further, in the test tool, the connection between the switch K and the resistor R301 and the multimeter is made using a banana plug.

[0037] Further, the automatic voltage regulator of the generator power supply system further includes an auxiliary power supply, which supplies power to the PWM control circuit.

[0038] Furthermore, the automatic voltage regulator of the generator power system also includes an overcurrent protection circuit, which is connected to the PWM control circuit and the generator circuit to obtain the generator's current signal.

[0039] The beneficial effects of this invention are as follows: The open-loop debugging method for the voltage regulator point of the power supply system of the electrically excited generator proposed in this invention improves the debugging efficiency by testing the reference voltage and sampling voltage of the voltage regulator inside the voltage regulator and then calculating the debugging resistor value. The debugging time of the voltage regulator point is shortened from about 12 minutes per unit in the original debugging method to less than 2 minutes. At the same time, it avoids the “soldering-unsoldering-soldering” process of soldering potentiometers at the debugging resistor position, then unsoldering the potentiometers, and finally replacing them with fixed resistors, thus improving the reliability of the solder pads. Attached Figure Description

[0040] Figure 1 This is a circuit diagram of the sampling circuit and voltage regulator of the present invention;

[0041] Figure 2 This is a schematic block diagram of the generator power supply system used in this invention;

[0042] Figure 3 This is a schematic diagram of the connection of the test fixture used in this invention. Detailed Implementation

[0043] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0044] First, the closed-loop working principle of the electrically excited generator power supply system is analyzed, and then the technical solution is described.

[0045] 1. Closed-loop working principle of generator system

[0046] Taking a unidirectional excitation voltage regulator that uses pulse width modulation (PWM) to control the excitation current as an example to illustrate its working principle, the block diagram of the power system consisting of the generator and the voltage regulator is as follows: Figure 2 As shown.

[0047] As the generator's speed increases, when the speed reaches a specified value, the secondary excitation power supply momentarily intervenes to establish voltage in the system, and then the power system operates in closed-loop mode. Initially, the generator speed is low, and the generator's output voltage V... e Lower, V e The sampling signal V is obtained through the "sampling circuit". f The voltage is lower than the reference voltage V in the PWM controller. r The voltage regulator in the PWM controller ( Figure 1) the error signal amplified output is higher, and the PWM signal output after comparing with sawtooth wave is wider, the signal is driven by "isolated driving circuit" and "power switch" to output wider excitation voltage V o , the output voltage V e of the generator is raised until reaching the voltage V w of the voltage regulator's stable point;

[0048] When the output voltage V e of the generator is raised beyond the voltage V w of the stable point, the sampling signal voltage V f is higher than the reference voltage V r , the error signal output by the error amplifier is reduced, the PWM signal output after comparing with sawtooth wave is narrower, the excitation voltage V o is also narrower, the excitation current is reduced, the output voltage V w of the generator is reduced until reaching the voltage V e of the voltage regulator's stable point; When the output voltage V w of the generator is equal to the voltage V f of the stable point, the sampling signal voltage V r is equal to the reference voltage V fx , the PWM controller outputs stable pulse width, generates stable excitation current, and the closed loop system is in dynamic balance state, at this time , the voltage V of the sampling circuit is k times of the voltage V

[0049] , and the voltage V of the sampling circuit is k times of the voltage V .

[0050] According to the principle, the value of the debugging resistor in the sampling circuit can be determined by testing and calculating method in open loop state, so that the voltage division ratio k meets the formula (1).

[0051] 2 Technical scheme of calculating method to determine the debugging resistor

[0052] Firstly, when the debugging resistor R3 is Rx, the voltage V x of the sampling circuit meets the technical index requirements of the product, according to the formula (1), the following formula (2) can be obtained:

[0053] (2)

[0054] In the formula, V w : the voltage of the sampling circuit when the debugging resistor R3 is R x ;

[0055] V w : the voltage of the sampling circuit when the debugging resistor R3 is R x ;

[0056] V w : the voltage of the sampling circuit when the debugging resistor R3 is R x ;r : reference voltage, measurable (known);

[0057] R1, R2: unknown (actual value is difficult to measure online);

[0058] R x : parameter to be solved.

[0059] Second, in order to solve R x , two tests are needed in two states, adding two equations.

[0060] When R3 is not installed, the sampling voltage is:

[0061] ……………………………(3)

[0062] In the formula: V f0 : sampling voltage when R3 is not installed, measurable (known).

[0063] Third, a resistor with known resistance is connected in parallel across R2, the resistance can be the nominal value of R3 in the design drawing, and the sampling voltage is:

[0064] ………(4)

[0065] In the formula: V f3 : sampling voltage after connecting R301 in parallel, measurable (known); R3: measurable (nominal value, known).

[0066] Fourth, solve equations (2), (3), and (4) together:

[0067] ………………………………………(5)

[0068] R x is the required debugging resistor.

[0069] 3 When debugging, the specific debugging steps include:

[0070] First, make a test tool according to Figure 3 , where R301 takes the nominal value in the design drawing;

[0071] Second, adjust the input voltage V in to about 0.5V lower than the stable voltage point V w , and adjust the output current to the specified value in the debugging specification. The clip on the test tool (one end of the resistor R301 connected to the negative pole of the multimeter) is connected to the negative pole of the power supply. ​​

[0072] Third step, in the state of switch K is off, use the probe of test tool (one end of switch K is connected with the positive pole of multimeter) to contact the left end of R5 (one end which is not connected with operational amplifier U1) to measure V r ;

[0073] Fourth step, use the probe of tool to contact the left end of R4 to measure V f0 ;

[0074] Fifth step, close switch K, use the probe of test tool (one end of switch K is connected with the positive pole of multimeter) to contact the left end of R4 (the connecting end of resistor R4 and R3) to measure V f3 ;

[0075] Sixth step, calculate the value of R x according to formula (5);

[0076] Seventh step, take the resistor which is closest to the resistance value of R x as the determined debugging resistor.

[0077] Explanation:

[0078] 1) need to test V r , V f0 , V f3 under the same input voltage;

[0079] 2) if the calculated R x is negative, increase R2 by one step and test and calculate again;

[0080] 3) formula (5) is derived from the example of single excitation voltage regulator, but it is also applicable to double excitation voltage regulator.

Claims

1. A fixture for open-loop debugging of the voltage stabilization point in an electrically excited generator power supply system, characterized in that: The debugging fixture includes a sampling circuit and a testing fixture. The sampling circuit is installed in the automatic voltage regulator of the generator power system. The sampling circuit includes resistors R1-R3, one end of which is connected to the generator output voltage V. e One end of R5 is connected to one end of R1, and the other end of R2 is grounded; one end of R3 is connected to the other end of R1, and the other end of R3 is grounded. R3 is the debugging resistor to be tested. The automatic voltage regulator also includes a PWM control circuit, which contains a voltage regulator. The voltage regulator includes resistors R4-R6, operational amplifier U1, and capacitor C1. One end of resistor R4 is connected to the other end of R1, and the other end is connected to the negative input terminal of operational amplifier U1. One end of R5 is connected to the reference voltage V. r One end of the capacitor is connected to the positive input terminal of the operational amplifier U1, the other end of the capacitor C1 is connected to one end of the resistor R6, and the other end of the resistor R6 is connected to the negative input terminal of the operational amplifier U1. The test fixture includes a switch K and a test resistor R301. One end of the switch K is connected to the positive terminal and probe of a multimeter, and the other end is connected to one end of the resistor R301. The other end of the resistor R301 is connected to the negative terminal of the power supply and the negative terminal of the multimeter.

2. A debugging method for the open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system as described in claim 1, characterized in that: Let the resistance of the test resistor R3 be R. x During debugging, R3 was not connected to the sampling circuit. A test fixture was used for debugging, specifically including the following steps: Step 1, convert the generator's input voltage V in Adjust to the voltage regulator point V w Set the voltage to 0.5V, take the resistance value of resistor 301 as the design nominal value of resistor R3 to be debugged, install the debugging fixture, and connect the other end of resistor R301 to the negative terminal of the power supply. Step 2: With switch K open, use the probe of the debugging fixture to contact one end of resistor R5, and measure the reference voltage V using the multimeter reading. r The value; Step 3: With switch K open, use the probe of the debugging fixture to contact the end where resistor R4 and R1 are connected. Measure the sampling voltage V of resistor R2 without resistor R301 connected in parallel using a multimeter. f0 The value; Step 4: Close switch K, and use the probe of the debugging fixture to contact the end where resistor R4 and R1 are connected. Measure the sampling voltage V when resistor R2 is connected in parallel with resistor R301 using the multimeter reading. f3 The value; Step 5, according to the formula Calculate R X The resistance value is given by the formula, where R3 is the design nominal value; Step 6: Select the R that is closest to the value calculated in Step 5 in practical applications. X The resistor at the resistance value setting is connected to the sampling circuit as the adjustment resistor R3.

3. The debugging method of the open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system as described in claim 2, characterized in that: In step 5, the formula The derivation process includes the following steps: Step 501, when the generator output voltage V e Equal to the voltage at the regulator point V w At that time, the sampling signal voltage V f Equal to the reference voltage V r The PWM controller outputs a stable pulse width, generating a stable excitation current. The closed-loop system is in a dynamic equilibrium state at this time. Let the voltage division ratio of the sampling circuit be k, then: …………………………………（1） Step 502, let the resistance of the adjustment resistor R3 to be determined be R. x Stabilizing point V w To meet the product's technical specifications, according to formula (1): …………（2） In the formula: V fx The resistance value of the adjustment resistor is R. x Sampling voltage at time; V w The regulated voltage required by the product's technical specifications; V r Reference voltage, measurable; R1, R2: values ​​unknown; R x Parameters to be determined; Step 503: To solve for Rx, tests need to be performed under two conditions, adding two equations: R301 is not installed when not under testing, and the input voltage... At that time, the sampling voltage is: ……………………………（3） In the formula: V f0 The sampling voltage when R301 is not installed can be measured; A resistor R301 with a known resistance value is connected in parallel across R2. The resistance value is taken from the nominal value of R3 during the design. The input voltage... At that time, the sampling voltage is: …………（4） In the formula: V f3 R3: The voltage sampled after parallel connection of R301 can be measured; R3: Design nominal value; Step 504, solving equations (2), (3), and (4) simultaneously yields: ………………………………………（5） Among them, R x This refers to the resistance value of the required adjustment resistor.

4. The debugging method of the open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system as described in claim 2, characterized in that: In step 1, the generator's power output current also needs to be adjusted to the value specified in the commissioning guidelines.

5. The debugging method of the open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system as described in claim 2, characterized in that: In step 5, if Rx is calculated to be negative, then replace R2 with a larger resistance value and repeat steps 1-5 until Rx is negative. x It is a positive value.

6. The debugging method of the open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system as described in claim 2, characterized in that: In steps 2-3, V is performed. r V f0 and V f3 During testing, the input voltage V must be maintained. e constant.

7. The open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system as described in claim 1, characterized in that: The test fixture uses clips to connect resistor R301 to the negative terminal of the power supply.

8. The open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system as described in claim 1, characterized in that: The connection between the switch K and resistor R301 in the test fixture and the multimeter is made using banana plugs.

9. The open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system as described in claim 1, characterized in that: The automatic voltage regulator of the generator power system also includes an auxiliary power supply, which supplies power to the PWM control circuit.

10. The open-loop debugging fixture for the voltage regulation point of an electrically excited generator power supply system as described in claim 1, characterized in that: The automatic voltage regulator of the generator power system also includes an overcurrent protection circuit, which is connected to the PWM control circuit and the generator circuit to obtain the generator's current signal.

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