Network construction and operation method of renewable energy integrated system integrating synchronous measurement information

Abstract

The present invention provides a renewable energy integrated system grid operation method integrating synchronous measurement information, which belongs to the field of energy and includes the following steps: Step 1: integrating the synchronous measurement information of each node at the power generation end and the power transmission end of the power system, and constructing a general model of active-phase angle control for the grid operation of the converter; Step 2: using the general model of active-phase angle control for the grid operation of the converter in step 1, modeling a distributed generator multi-machine parallel system with n converters performing active-phase angle control, analyzing the operating mechanism of the converter multi-machine parallel operation, and performing grid operation control. The present invention realizes the safe and stable operation of a new power system containing renewable energy distributed generation.

Description

Technical Field

[0001] The present invention belongs to the field of energy, and in particular relates to a network construction and operation method of a renewable energy integrated system integrating synchronous measurement information. Background Art

[0002] With the large-scale development of renewable energy distributed generation, in order to cope with the problem of lack of inertia support in the new power system, renewable energy distributed generation converters mostly adopt grid control strategies. At present, active power-phase angle grid control integrates the synchronous measurement information of each node at the power generation and transmission ends of the power system, which is conducive to the safe and stable operation of the power system.

[0003] At present, the research on active power-phase angle grid control lacks universal general models and multi-machine parallel models. The parallel operation of multiple machines in converter active power-phase angle grid control is only analyzed from the result level, and there is a lack of analysis of its operation mechanism. Summary of the invention

[0004] To solve the above technical problems, the present invention provides a renewable energy integrated system grid operation method integrating synchronous measurement information, analyzes the operating mechanism of converter active power-phase angle grid control of multiple machines in parallel operation, and better guides grid operation.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] The network construction and operation method of the integrated renewable energy system integrating synchronous measurement information comprises the following steps:

[0007] Step 1: Integrate the synchronous measurement information of each node at the power generation and transmission ends of the power system to build a general active power-phase angle control model for the grid operation of the converter;

[0008] Step 2: Using the general model of active power-phase angle control of the converter grid operation in step 1, a distributed generator multi-machine parallel system with n converters performing active power-phase angle control is modeled, the operating mechanism of the converter multi-machine parallel operation is analyzed, and grid operation control is performed.

[0009] Beneficial effects:

[0010] 1. The present invention constructs a universal active power-phase angle control model for converter grid operation, which can model a variety of active power / phase angle relationships by integrating the synchronous measurement information of each node at the power generation end and the power transmission end of the power system.

[0011] 2. This paper constructs a phase angle-active power variation model for the parallel operation of multiple machines in the converter grid control, which is beneficial to the analysis of the operating mechanism of the parallel operation of multiple machines in the grid converter, and is conducive to the safe and stable operation of the new power system containing distributed power generation of renewable energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A flowchart of a method for networking and operating a renewable energy integrated system integrating synchronous measurement information provided by the present invention;

[0013] Figure 2 This is the converter active power-phase angle droop characteristic diagram before the measurement information of each node at the power generation and transmission ends of the power system is incorporated. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0015] like Figure 1 As shown, the network construction and operation method of the renewable energy integrated system integrating synchronous measurement information of the present invention comprises the following steps:

[0016] Step 1: Integrate the synchronous measurement information of each node at the power generation and transmission ends of the power system to build a universal active power-phase angle control model for converter grid operation:

[0017] The universal active power-phase angle control model of converter grid operation is shown in formula (1):

[0018] (1)

[0019] (2)

[0020] Among them, s is the frequency domain variable of Laplace transform, A i is the coefficient of the quadratic term in the denominator, B i is the coefficient of the first-order term in the denominator, C i is the coefficient of the denominator constant term, D i is the coefficient of the numerator quadratic term, E i is the coefficient of the first-order term in the numerator, F i is the coefficient of the numerator constant term; i is the i-th distributed generator, is the phase angle reference value, is the load voltage phase angle, The phase angle of the converter output voltage when the distributed generator set is unloaded, is the droop coefficient of the i-th active power-phase angle droop control, is the active power output of the i-th converter, is the active power reference value output by the i-th converter, is the proportional coefficient of the PI controller, is the derivative coefficient for the PI controller, is the load voltage phase angle. , , , , They are all intermediate parameters, and their values ​​are shown in formula (2).

[0021] The derivation process of the universal active power-phase angle control general model of converter grid operation includes:

[0022] Step 11: Construct the characteristic equation of active power-phase angle droop control as:

[0023] (3)

[0024] like Figure 2 The figure shows the converter active power-phase angle droop characteristic diagram before the measurement information of each node at the power generation and transmission ends of the power system is integrated. Where i is the i-th distributed generator, The phase angle of the converter output voltage when the distributed generator set is unloaded, the droop coefficient of the active power-phase angle droop control of the i-th unit, is the active power output of the i-th converter, The active power reference value output by the i-th converter.

[0025] The reference value of the converter output voltage phase angle obtained by formula (3) is The actual phase angle of the inverter output voltage The phase angle reference value is obtained by making a difference through the PI controller , as shown in formula (4):

[0026] (4)

[0027] in, is the proportional coefficient of the PI controller, is the derivative coefficient for the PI controller, is the load voltage phase angle, and s is the frequency domain variable of Laplace transform.

[0028] If the synchronous measurement information of each node at the power generation and transmission end of the power system is obtained , which has a phase angle reference with the converter output voltage of Add and directly output the phase angle reference value , as shown in formula (5):

[0029] (5)

[0030] set up , and substituting it into formula (5) we get:

[0031] (6)

[0032] Among them, M i , L i , K i They are the coefficients of the denominator of formula (4): M i is the coefficient of the quadratic term in the denominator, L i is the coefficient of the first-order term in the denominator, K i is the coefficient of the denominator constant term.

[0033] It can be seen from formula (6) that the active reference value can be changed directly To change the phase angle reference value .

[0034] Substituting formula (3) into formula (4) and formula (6), we obtain:

[0035] (7)

[0036] (8)

[0037] Arranging formula (7) and formula (8) yields:

[0038] (9)

[0039] (10)

[0040] If the converter output active power reference value If the rated capacity is fixed, formula (10) can be rewritten as:

[0041] (11)

[0042] If the expression of formula (11) is to be the same as that of formula (9), the numerator and denominator of formula (11) and formula (9) should be equal, that is, M i =0, , , then formula (11) can be rewritten as:

[0043] (12)

[0044] in, , .

[0045] Step 12: Arrange formula (9) into a unified form as shown in formula (1), then:

[0046] (13)

[0047] in, is the coefficient of the quadratic term in the denominator, is the coefficient of the first-order term in the denominator, is the coefficient of the denominator constant term, is the coefficient of the numerator quadratic term, is the coefficient of the first-order term in the numerator, is the coefficient of the numerator constant term;

[0048] Comparing the two sides of the equation we can get:

[0049] (14)

[0050] in, ; ; .

[0051] Step 13: Arrange formula (12) into a unified form as shown in formula (1), then:

[0052] (15)

[0053] in, is the coefficient of the quadratic term in the denominator, is the coefficient of the first-order term in the denominator, is the coefficient of the denominator constant term, is the coefficient of the numerator quadratic term, is the coefficient of the first-order term in the numerator, is the coefficient of the numerator constant term.

[0054] Comparing the two sides of the equation we can get:

[0055] (16)

[0056] in, =0, =0, =0.

[0057] Step 14: Arrange formula (14) and formula (16) to obtain the general formula:

[0058] (17)

[0059] in, is the coefficient of the general numerator quadratic term, is the coefficient of the first-order term of the universal numerator, is the coefficient of the universal numerator constant term; when When , the general formula (1) expresses the formula (9); when When , the general formula (1) expresses the formula (12).

[0060] When , formula (17) represents formula (14); When , formula (17) represents formula (16).

[0061] when , , , , When any value is 0 or 1, it is Formula (2). In addition to Formula (14) and Formula (16), Formula (2) can also express other situations not specifically described in the present invention, that is, Formula (14) and Formula (16) are two of the many expressions that can be expressed by Formula (2).

[0062] Step 15: Extend formula (17) into a universal active power-phase angle control model for converter grid operation. The value is no longer limited to and , but can be arbitrarily set to 0 or 1. Therefore, formula (1) is no longer limited to describing formula (9) and formula (12), but can describe a variety of active power / phase angle relationships. Finally, formula (1) and formula (2) are summarized as a universal active power-phase angle control general model for converter grid operation.

[0063] Step 2: Modeling of a multi-machine parallel system of distributed generators with active power-phase angle control of n converters, including:

[0064] Step 21: From formula (1), it can be obtained that the phase angle reference value of the voltage-current double closed loop of the first distributed generator converter is As shown in formula (18):

[0065] (18)

[0066] Phase angle reference value of voltage-current double closed loop of the i-th distributed generator converter As shown in formula (19):

[0067] (19)

[0068] Phase angle reference value of voltage and current double closed loop of the nth distributed generator converter As shown in formula (20):

[0069] (20)

[0070] Combining formula (18), formula (19), and formula (20) into a matrix equation is:

[0071] (twenty one)

[0072] Rewritten as phase angle reference value Active power conversion As shown in formula (22), .

[0073] (twenty two)

[0074] Step 22: As shown in formula (23), is the voltage reference value obtained by reactive power-voltage control and the phase angle reference value Combined to get the d-axis reference value of voltage and q-axis reference value , and After passing through the voltage and current dual closed-loop module and the pulse width modulation (PWM) module, the final PWM wave is transmitted to the converter gate to control the on and off of the converter switching device.

[0075] (twenty three).

Claims

1. A method for networking and operating a renewable energy integrated system integrating synchronous measurement information, characterized in that: The steps include: Step 1: Integrate the synchronous measurement information of each node at the power generation and transmission ends of the power system to construct a general active power-phase angle control model for the inverter grid operation: （1） （2） Among them, s is the frequency domain variable of Laplace transform, A i is the coefficient of the quadratic term in the denominator, B i is the coefficient of the first-order term in the denominator, C i is the coefficient of the denominator constant term, D i is the coefficient of the numerator quadratic term, E i is the coefficient of the first-order term in the numerator, F i is the coefficient of the numerator constant term; i represents the i-th distributed generator, is the phase angle reference value, is the load voltage phase angle, The phase angle of the converter output voltage when the distributed generator set is unloaded, is the droop coefficient of active power-phase angle droop control, is the active power output of the i-th converter, is the active power reference value output by the i-th converter, is the proportional coefficient of the PI controller, is the differential coefficient of the PI controller; , , , , All are intermediate parameters, and their values ​​refer to formula (2); Step 2: Using the general model of active power-phase angle control of the converter grid operation in step 1, a distributed generator multi-machine parallel system with n converters performing active power-phase angle control is modeled, the operating mechanism of the converter multi-machine parallel operation is analyzed, and grid operation control is performed, including: Step 21: From formula (1), the parallel operation model of n distributed generator converters is obtained as follows: （21） Rewritten as phase angle reference value Active power conversion The formula is as shown in formula (22), where ; （22）。 2. The method for networking and operating a renewable energy integrated system integrating synchronous measurement information according to claim 1, characterized in that: The derivation process of the general model of active power-phase angle control of the converter grid operation in step 1 includes: The inverter output voltage phase angle reference value obtained by the inverter active power-phase angle droop control The actual phase angle with the inverter output voltage The phase angle reference value is obtained by making a difference through the PI controller , as shown in formula (4): （4）。 3. The method for networking and operating a renewable energy integrated system integrating synchronous measurement information according to claim 1, characterized in that: The general model of active power-phase angle control of converter grid operation obtains the phase angle difference through the synchronous measurement information of each node at the power generation end and the power transmission end of the power system. , which has a phase angle reference with the converter output voltage of Add and directly output the phase angle reference value ,set up ,get: （6） Among them, M i is the coefficient of the quadratic term in the denominator, L i is the coefficient of the first-order term in the denominator, K i is the coefficient of the denominator constant term.

4. The method for networking and operating a renewable energy integrated system integrating synchronous measurement information according to claim 3, characterized in that: By directly changing the output active power reference value of the i-th converter To change the phase angle reference value ; If the active power reference value output by the i-th converter is Fixed to rated capacity, substitute formula (3) into formula (4) and formula (6) and arrange them to obtain: （9） （11） Formula (3) is: （3） If the expression of formula (11) is the same as formula (9), the numerator and denominator of formula (11) should be equal to those of formula (9), that is, Mi=0, , , sorted out , .

5. The method for networking and operating a renewable energy integrated system integrating synchronous measurement information according to claim 4, characterized in that: The step 1 also includes: Formula (9) is organized into a unified form as shown in formula (1), and the general formula is obtained: （17） in, is the coefficient of the general numerator quadratic term, is the coefficient of the first-order term of the universal numerator, is the coefficient of the universal numerator constant term; when When , formula (1) expresses formula (9); when When , formula (1) means formula (12); Formula (17) is extended to a universal active power-phase angle control model for converter grid operation; It can take any value of 0 or 1 to describe a variety of active power / phase angle relationships, and finally obtain formula (1) and formula (2) as the general active power-phase angle control model for converter grid operation.

6. The method for networking and operating a renewable energy integrated system integrating synchronous measurement information according to claim 5, characterized in that: The step 2 also includes: Step 22: As shown in formula (23), is the voltage reference value obtained by reactive power-voltage control and the phase angle reference value Combined to get the d-axis reference value of voltage and q-axis reference value , and After passing through the voltage and current double closed-loop module and the pulse width modulation module, the pulse width modulation wave is finally transmitted to the converter gate to control the on and off of the converter switch device: （23）。

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